Protocol for broadband data communication over a shared medium

TLDR: In this article, the authors propose a DVB modem transmission framing synchronization and FEC standards at the physical layer, which support a full range of 16 to 256 QAM transmission rates in both 6 MHz and 8 MHz channels.

Abstract: Network architectures and data communication protocols for supporting both downstream and upstream transport of digital data between a headend facility and multiple downstream network terminals over a shared communication medium include downstream framing protocols compatible with DVB modem transmission framing synchronization and FEC standards at the physical layer, which support a full range of 16 to 256 QAM transmission rates in both 6 MHz and 8 MHz channels. The downstream data frames are formed by one or more repeating pairs of DVB compatible frame slots, wherein each downstream frame is transmitted over the same interval, e.g., 250 usec in preferred formats, regardless of the number of DVB slot pairs it contains. All downstream frame rates are supported by a single upstream data rate. Upstream bandwidth is allocated based on a selected set of operating criteria and service type priorities, based on both a polling basis and a contention basis, on one or more in-band RF subcarrier channels.